Module Access Device
Device that allows you to directly access the buffer memory of intelligent function modules connected to the CPU module from
the CPU module.
Specified by U [module number of intelligent function modules]\[buffer memory address].
Processing speed of reading/writing by module access device is faster than using FROM/TO instruction. (Example: MOV
U2\G11 D0) When reading the buffer memory of a module access device and executing another process by 1 instruction, the
processing speed would be approximately the total of processing speed of FROM/TO instruction and processing speed of
instruction. (Example: +U2\G11 D0 D10)
If reading/writing data of the buffer memory using module access device at least 2 times in the program, you
can speed up processing time by reading/writing at a single place in the program using a FROM/TO
• Writing using multiple module access devices
• Writing at single place in program using TO instruction
• If module access device is used in an interrupt program with the priority 1, operation error (3580H) occurs. Module access
device operates in an interrupt program with the priority 2 or 3.
• When FROM/TO instruction is executed in an interrupt program to an FX3 intelligent function module that is connected to
the bus conversion module or later, operation error (3580H) occurs.
Stores data to a device such as
data register (D).
Writes data once in the program.
26.4 Module Access Device